The invention relates to a magnetic cassette recorder comprising a magnetic head which can be translated between an operating position, in which the head cooperates with a magnetic tape in an inserted cassette, and a withdrawn position, in which the head is clear of an inserted cassette, and which is, moreover, pivotable about a pivotal axis between a first angular position and a second angular position, which head is electrically connected to stationary parts of the recorder by means a flat flexible multiple electrical conductor, such as a foil carrying printed electrical conductor tracks or a flat cable.
Recorders of this type are used mainly for audio applications employing cassettes for recording and reproduction in both a forward and a reverse direction, such as the well-known Analog Compact Cassette recorders and the more recent Digital Compact Cassette recorders. In recorders of this type the tape is scanned in two adjacent parallel zones, one zone being scanned in one direction and the other zone being scanned in the other direction. The magnetic head may be constructed in such a manner that in fixed position it is capable of cooperating correctly with each of the zones in each of the two tape transport directions. However, in many cases a head of simpler construction is used, which must be reversed to cooperate with the relevant zone of the tape in the reverse transport direction. With this construction the head requires a smaller number of active transducing gaps than a head for a recorder using the first-mentioned construction. However, a consequence is that a mechanism must be provided for the reversal of the head, which partly outweighs the price advantage gained by the use of a simpler head. Some heads have many transducing gaps, such as the heads for DCC recorders, which have at least nine digital write gaps and nine digital read gaps and a number of additional gaps, such as two analog read gaps, i.e. at least twenty transducing gaps in total. Consequently, a large number of electrical conductors are needed to transfer signals between the head and the stationary electronic circuitry of the recorder. Providing a reliable electrical connection between pivoting and translating heads having such a large number of transducing gaps and the stationary parts of the recorder at a moderate cost price is a major technical challenge.
In the currently non-prepublished EP Application 92203768.4 (PHO 91-512, herewith incorporated by reference) it has been proposed to mount the head on a hollow pivotal shaft and to construct the electrical conductor as a two-part printed foil connected to the magnetic head through the hollow shaft. Mounting the foil is difficult, the space available for the foil inside the hollow shaft is small, and the length of the foil is comparatively great, resulting in a large distance between the head and the stationary parts to which the foil is connected.
It is an object of the invention to provide a recorder of the type defined in the opening paragraph, in which the magnetic head is connected to the stationary parts of the recorder in an effective and economical manner and so as to contribute to minimal dimensions of the recorder.
To this end the recorder in accordance with the invention is characterized in that the conductor is arranged as a cylindrical spiral about the pivotal axis and its end which is remote from the head is connected directly to the stationary parts of the recorder, so that translations of the head in the axial direction result in the spiral being extended/compressed and pivotal movements of the head result in the spiral being coiled/uncoiled.
The advantage of the invention is that only a short conductor is required and that this conductor can be mounted rapidly and simply. Mounting flat conductors is comparatively expensive and problematic. The favourable effect is obtained by the use of a spiral which is deformable in two directions, i.e. both in the translating and in the pivoting direction. This means that no separate provisions are needed for each of the two directions.
An advantageous embodiment of the invention is characterized in that the conductor end which is remote from the head is a conductor portion which extends parallel to the direction of the pivotal axis. The conductor is short, yet it can easily be connected to the stationary parts of the recorder, for example by means of a connector. Moreover, this embodiment is very suitable for use with a connector in the form of flat cable. Such cables are readily available only as straight cables having their ends cut at right angles to the sides of the cable.
A further embodiment of the invention is characterized in that the conductor end which is remote from the head is a conductor portion which extends transversely of the direction of the pivotal axis. This embodiment is particularly suitable for use with printed foils. Conductors of this type are available in almost any form and consequently provide much freedom as regards the location of the parts to be interconnected inside an apparatus.
A further embodiment of the invention is characterized in that the conductor end which is remote from the head is disposed in a plane which extends at least substantially tangentially to the outer turn of the spiral. By means of this embodiment it is avoided that the conductor part adjacent the spiral is bent unnecessarily and, hence, that the conductor is subjected to an unnecessarily high mechanical load.
A further embodiment of the invention is characterized in that the conductor end which is remote from the head extends at an acute angle to the direction of the pivotal axis. This embodiment is conceivably more favourable in order to reduce stresses in the conductor. These stresses may be caused in particular by the translation of the head.